[HDDS-4023] Delete closed container after all blocks have been deleted

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.1.0
• Labels: pull-request-available
• Target Version/s: 1.1.0
• Assignee: Sammi Chen
• Reporter: Sammi Chen
• Created: 24/Jul/20 03:39
• Updated: 10/Nov/20 08:42
• Resolved: 10/Nov/20 08:42

Description

One of our use case is customers delete old objects and files regularly. Once the old files are deleted, there are many containers with no user data.

The goal of this task is delete all these containers to reduce the metadata footprint of both dn and scm.

Here is the container state machine involved,

                   Container key count &size 0                    Container replica count 0
CLOSED       ---------------------------------> DELETING  --------------------------------> DELETED
                   DELETE event                                           CLEANUP event

Currently when Container is in DELETED state, it still exists in SCM memory and DB.

Issue Links

• Dependent: HDDS-4037 Incorrect container numberOfKeys and usedBytes in SCM after key deletetion
• links to: GitHub Pull Request #1338